Touch panel and display device using the same

ABSTRACT

A touch panel includes a transparent substrate, a transparent conductive layer, and at least two electrodes. The transparent conductive layer is formed on a surface of the transparent substrate. The transparent conductive layer includes at least two carbon nanotube layers, and each carbon nanotube layer includes a plurality of carbon nanotubes arranged along a same direction. The carbon nanotubes in two adjacent carbon nanotube layers are arranged along the same direction. The electrodes are electrically connected with the transparent conductive layer. Further, a display device using the touch panel is also included.

RELATED APPLICATIONS

This application is related to commonly-assigned applications entitled,“TOUCH PANEL”, filed ______ (Atty. Docket No. US17449); “TOUCH PANEL”,filed ______ (Atty. Docket No. US17448); “TOUCH PANEL AND DISPLAY DEVICEUSING THE SAME”, filed ______ (Atty. Docket No. US17861); “TOUCH PANELAND DISPLAY DEVICE USING THE SAME”, filed ______ (Atty. Docket No.US17818); “TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”, filed ______(Atty. Docket No. US17820); “TOUCH PANEL AND DISPLAY DEVICE USING THESAME”, filed ______ (Atty. Docket No. US17862); “TOUCH PANEL AND DISPLAYDEVICE USING THE SAME”, filed ______ (Atty. Docket No. US17863); “TOUCHPANEL AND DISPLAY DEVICE USING THE SAME”, filed ______ (Atty. Docket No.US18263); “TOUCHABLE CONTROL DEVICE”, filed ______ (Atty. Docket No.US18262); “TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”, filed ______(Atty. Docket No. US17889); “TOUCH PANEL AND DISPLAY DEVICE USING THESAME”, filed ______ (Atty. Docket No. US17884); “TOUCH PANEL AND DISPLAYDEVICE USING THE SAME”, filed ______ (Atty. Docket No. US17885); “TOUCHPANEL AND DISPLAY DEVICE USING THE SAME”, filed ______ (Atty. Docket No.US17886); “TOUCH PANEL, METHOD FOR MAKING THE SAME, AND DISPLAY DEVICEADOPTING THE SAME”, filed ______ (Atty. Docket No. US17887); “TOUCHPANEL AND DISPLAY DEVICE USING THE SAME”, filed ______ (Atty. Docket No.US17864); “TOUCH PANEL, METHOD FOR MAKING THE SAME, AND DISPLAY DEVICEADOPTING THE SAME”, filed ______ (Atty. Docket No. US17865); “TOUCHPANEL AND DISPLAY DEVICE USING THE SAME”, filed ______ (Atty. Docket No.US18266); “TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”, filed ______(Atty. Docket No. US18257); “METHOD FOR MAKING TOUCH PANEL”, filed______ (Atty. Docket No. US18069); “METHOD FOR MAKING TOUCH PANEL”,filed ______ (Atty. Docket No. US18068); “TOUCH PANEL AND DISPLAY DEVICEUSING THE SAME”, filed ______ (Atty. Docket No. US17841); “TOUCH PANELAND DISPLAY DEVICE USING THE SAME”, filed ______ (Atty. Docket No.US17888); “TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”, filed ______(Atty. Docket No. US17860); “TOUCH PANEL AND DISPLAY DEVICE USING THESAME”, filed ______ (Atty. Docket No. US17857); “TOUCH PANEL AND DISPLAYDEVICE USING THE SAME”, filed ______ (Atty. Docket No. US18258); “TOUCHPANEL AND DISPLAY DEVICE USING THE SAME”, filed ______ (Atty. Docket No.US18264); “TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”, filed ______(Atty. Docket No. US18267); “TOUCH PANEL, METHOD FOR MAKING THE SAME,AND DISPLAY DEVICE ADOPTING THE SAME”, filed ______ (Atty. Docket No.US17839); “ELECTRONIC ELEMENT HAVING CARBON NANOTUBES”, filed ______(Atty. Docket No. US18066); and “TOUCH PANEL, METHOD FOR MAKING THESAME, AND DISPLAY DEVICE ADOPTING THE SAME”, filed ______ (Atty. DocketNo. US17858). The disclosures of the above-identified applications areincorporated herein by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to a carbon-nanotube-based touch panel anda display device using the same.

2. Discussion of Related Art

Following the advancement in recent years of various electronicapparatuses, such as mobile phones, car navigation systems and the like,toward high performance and diversification, there has been continuousgrowth in the number of electronic apparatuses equipped with opticallytransparent touch panels at the front of their respective displaydevices (e.g., a display such as a liquid crystal panel). A user of anysuch electronic apparatus operates it by pressing or touching the touchpanel with a finger, a pen, a stylus, or a like tool while visuallyobserving the display device through the touch panel. A demand thusexists for such touch panels that are superior in visibility andreliable in operation.

At present, different types of touch panels, including resistance,capacitance, infrared, and surface sound-wave types, have beendeveloped. The capacitance-type touch panel has several advantages suchas high accuracy and excellent transparency, and thus has been widelyused.

A conventional capacitance-type touch panel includes a glass substrate,a transparent conductive layer, and four electrodes. The material of thetransparent conductive layer is, typically, selected from a groupconsisting of indium tin oxide (ITO) and antimony tin oxide (ATO). Theelectrodes are made of metal and separately formed on a surface of thetransparent conductive layer. Further, a protective layer is formed onthe surface of the transparent conductive layer that faces away from thesubstrate. The material of the protective layer has insulative andtransparent characteristics.

In operation, an upper surface of the touch panel is pressed/touchedwith a touch tool, such as a user's finger or an electrical pen/stylus.Visual observation of a screen on the liquid crystal display deviceprovided on a backside of the touch panel is possible. In use, becauseof an electrical field of the user, a coupling capacitance forms betweenthe user and the transparent conductive layer. For high frequencyelectrical current, the coupled capacitance is a conductor, and thus thetouch tool takes away a little current from the touch point. Currentflowing through the four electrodes cooperatively replaces the currentlost at the touch point. The quantity of current supplied by the fourelectrodes is directly proportional to the distances from the touchpoint to the electrodes. A touch panel controller is used to calculatethe proportion of the four supplied currents, thereby detectingcoordinates of the touch point on the touch panel.

The optically transparent conductive layer (e.g., ITO layer) isgenerally formed by means of ion-beam sputtering, and this method isrelatively complicated. Furthermore, the ITO layer has generally poormechanical durability, low chemical endurance, and uneven resistanceover an entire area of the touch panel. Additionally, the ITO layer hasrelatively low transparency. All the above-mentioned problems of the ITOlayer tend to yield a touch panel with somewhat low sensitivity,accuracy, and brightness.

What is needed, therefore, is to provide a durable touch panel with highsensitivity, accuracy, and brightness, and a display device using thesame.

SUMMARY

A touch panel includes a substrate, a transparent conductive layer, andat least two electrodes. The transparent conductive layer is formed on asurface of the substrate. The transparent conductive layer includes atleast two stacked carbon nanotube layers, and each carbon nanotube layerincludes a plurality of carbon nanotubes arranged along a samedirection. Carbon nanotubes of adjacent carbon nanotube layers arearranged along the same direction. The electrodes are electricallyconnected with the transparent conductive layer. Further a displaydevice using the touch panel is also included.

Other advantages and novel features of the present touch panel anddisplay device using the same will become more apparent from thefollowing detailed description of the present embodiments when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present touch panel and display device using thesame can be better understood with reference to the following drawings.The components in the drawings are not necessarily to scale, theemphasis instead being placed upon clearly illustrating the principlesof the present touch panel and display device using the same.

FIG. 1 is a schematic view of a partially assembled touch panel, inaccordance with a present embodiment.

FIG. 2 is a cross-sectional schematic view of the touch panel of FIG. 1,taken along a line II-II of FIG. 1.

FIG. 3 shows a Scanning Electron Microscope (SEM) image of a carbonnanotube film used in the touch panel of FIG. 1.

FIG. 4 is a structural schematic of a carbon nanotube segment.

FIG. 5 is essentially a schematic cross-sectional view of the touchpanel of the present embodiment used with a display element of a displaydevice, showing operation of the touch panel with a touch tool.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate at least one embodiment of the present touch panel anddisplay device using the same, in at least one form, and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION OF EMBODIMENTS

Reference will now be made to the drawings to describe, in detail,embodiments of the present touch panel and display device using thesame.

Referring to FIG. 1 and FIG. 2, a touch panel 20 includes a substrate22, a transparent conductive layer 24, a transparent protective layer26, and at least two electrodes 28. The substrate 22 has a first surface221 and a second surface 222 at opposite sides thereof respectively. Thetransparent conductive layer 24 is disposed on the first surface 221.The electrodes 28 are disposed on the sides of the transparentconductive layer 24 and electrically connected with the transparentconductive layer 24 for forming an equipotential surface on thetransparent conductive layer 24. The transparent protective layer 26covers the electrodes 28 and the exposed surface of the transparentconductive layer 24 that faces away from the substrate 22.

The substrate 22 has a planar structure or a curved structure. Thematerial of the substrate 22 is advantageously selected from the groupconsisting of glass, quartz, diamond, and plastics. Understandably, thesubstrate 22 is opportunely made from a transparent material, e.g.,either flexible or hard/stiff, depending on whether a flexible device isdesired or not. The substrate 22 is used to support the transparentconductive layer 24.

The transparent conductive layer 24 includes at least two stacked carbonnanotube layers. Each carbon nanotube layer contains a plurality ofcarbon nanotubes, and the carbon nanotubes therein are arranged along asame direction (i.e., collinear and parallel). Carbon nanotubes of allthe carbon nanotube layers are arranged along the same direction. Eachcarbon nanotube layer can be formed of a single carbon nanotube film ora plurality of coplanar carbon nanotube films. Thus, a length and awidth of the carbon nanotube layer can be set as desired. Referring toFIGS. 3 and 4, each carbon nanotube film comprises a plurality ofsuccessively oriented carbon nanotube segments 143 joined end-to-end byvan der Waals attractive force therebetween. Each carbon nanotubesegment 143 includes a plurality of carbon nanotubes 145 parallel toeach other, and combined by van der Waals attractive force therebetween.The carbon nanotube segments 143 can vary in width, thickness,uniformity and shape. The carbon nanotubes 145 in the carbon nanotubefilm 143 are also oriented along a preferred orientation. In the presentembodiment, a thickness of the carbon nanotube film is in an approximaterange from 0.5 nanometers to 100 micrometers. The carbon nanotubes inthe carbon nanotube film can be selected from a group consisting ofsingle-walled carbon nanotubes, double-walled carbon nanotubes, andmulti-walled carbon nanotubes. A diameter of each single-walled carbonnanotube is in an approximate range from 0.5 nanometers to 50nanometers. A diameter of each double-walled carbon nanotube is in anapproximate range from 1 nanometer to 50 nanometers. A diameter of eachmulti-walled carbon nanotube is in an approximate range from 1.5nanometers to 50 nanometers. In the following description, unless thecontext indicates otherwise, it will be assumed that each carbonnanotube layer is formed of a single carbon nanotube film.

A method for fabricating an above-described carbon nanotube filmincludes the steps of: (a) providing an array of carbon nanotubes, or,providing a super-aligned array of carbon nanotubes; (b) pulling out acarbon nanotube film from the array of carbon nanotubes, by using a tool(e.g., adhesive tape, pliers, tweezers, or another tool allowingmultiple carbon nanotubes to be gripped and pulled simultaneously).

In step (a), a given super-aligned array of carbon nanotubes can beformed by the substeps of: (a1) providing a substantially flat andsmooth substrate; (a2) forming a catalyst layer on the substrate; (a3)annealing the substrate with the catalyst layer in air at a temperaturein an approximate range from 700° C. to 900° C. for about 30 to 90minutes; (a4) heating the substrate with the catalyst layer to atemperature in the approximate range from 500° C. to 740° C. in afurnace with a protective gas therein; and (a5) supplying a carbonsource gas to the furnace for about 5 to 30 minutes and growing thesuper-aligned array of carbon nanotubes on the substrate.

In step (a1), the substrate can be a P-type silicon wafer, an N-typesilicon wafer, or a silicon wafer with a film of silicon dioxidethereon. A 4-inch P-type silicon wafer is used as the substrate in thepresent embodiment.

In step (a2), the catalyst can be made of iron (Fe), cobalt (Co), nickel(Ni), or any alloy thereof.

In step (a4), the protective gas can be made up of at least one ofnitrogen (N₂), ammonia (NH₃), and a noble gas. In step (a5), the carbonsource gas can be a hydrocarbon gas, such as ethylene (C₂H₄), methane(CH₄), acetylene (C₂H₂), ethane (C₂H₆), or any combination thereof.

The super-aligned array of carbon nanotubes can have a height of about50 microns to 5 millimeters and include a plurality of carbon nanotubes145 parallel to each other and approximately perpendicular to thesubstrate. The carbon nanotubes 145 in the array of carbon nanotubes canbe multi-walled carbon nanotubes, double-walled carbon nanotubes orsingle-walled carbon nanotubes. Diameters of the single-walled carbonnanotubes approximately range from 0.5 to 50 nanometers. Diameters ofthe double-walled carbon nanotubes approximately range from 1 to 50nanometers. Diameters of the multi-walled carbon nanotubes approximatelyrange from 1.5 to 50 nanometers.

The super-aligned array of carbon nanotubes formed under the aboveconditions is essentially free of impurities such as carbonaceous orresidual catalyst particles. The carbon nanotubes 145 in thesuper-aligned array are closely packed together by van der Waalsattractive force therebetween.

In step (b), the carbon nanotube film can be formed by the substeps of:(b1) selecting one or more carbon nanotubes having a predetermined widthfrom the array of carbon nanotubes; and (b2) pulling the carbonnanotubes to form nanotube segments 143 at an even/uniform speed toachieve a uniform carbon nanotube film.

In step (b1), quite usefully, the carbon nanotube segment 143 includes aplurality of carbon nanotubes 145 parallel to each other. The carbonnanotube segments 143 can be selected by using an adhesive tape as thetool to contact the super-aligned array of carbon nanotubes. In step(b2), the pulling direction is substantially perpendicular to thegrowing direction of the super-aligned array of carbon nanotubes.

More specifically, during the pulling process, as the initial carbonnanotube segments 143 are drawn out, other carbon nanotube segments 143are also drawn out end to end due to van der Waals attractive forcebetween ends of adjacent carbon nanotube segments 143. This process ofdrawing ensures a substantially continuous and uniform carbon nanotubefilm can be formed.

The carbon nanotube film includes a plurality of carbon nanotubesegments 143. The carbon nanotubes 145 in the carbon nanotube film areall substantially parallel to the pulling/drawing direction of thecarbon nanotube film, and the carbon nanotube film produced in suchmanner can be selectively formed having a predetermined width. Thecarbon nanotube film formed by the pulling/drawing method has superioruniformity of thickness and conductivity over a disordered carbonnanotube film. Further, the pulling/drawing method is simple, fast, andsuitable for industrial applications.

In the present embodiment, each carbon nanotube layer includes a singlecarbon nanotube film. Each carbon nanotube film comprises a plurality ofcarbon nanotube segments 143 which are in turn comprised of a pluralityof carbon nanotubes 145 arranged along a same direction. The directionis generally the pulling direction.

The width of the carbon nanotube film depends on a size of the carbonnanotube array. The length of the carbon nanotube film can be set asdesired. In one embodiment, when the substrate is a 4 inch type wafer asin the present embodiment, the width of the carbon nanotube film is inan approximate range from 0.5 nanometers to 10 centimeters, and thethickness of the carbon nanotube film is in the approximate range from0.5 nanometers to 100 micrometers. The carbon nanotubes in the carbonnanotube film can be selected from a group consisting of single-walledcarbon nanotubes, double-walled carbon nanotubes, and multi-layer carbonnanotubes. Diameters of the single-walled carbon nanotubes approximatelyrange from 0.5 to 50 nanometers. Diameters of the double-walled carbonnanotubes approximately range from 1 to 50 nanometers. Diameters of themulti-walled carbon nanotubes approximately range from 1.5 to 50nanometers.

It is noted that because the carbon nanotubes in the super-alignedcarbon nanotube array have a high purity and a high specific surfacearea, the carbon nanotube film is adherent in nature. As such, the firstcarbon nanotube film can be adhered directly to a surface of thesubstrate 22 without the use of an adhesive. In the alternative, otherbonding means can be applied. As such, at least two carbon nanotubelayers are arranged on top of one another, and the nanotubes arearranged along a same orientation.

The carbon nanotube film, once adhered to a surface of the substrate 22can be treated with an organic solvent. The carbon nanotube film can betreated by using organic solvent to soak the entire surface of thecarbon nanotube film. The organic solvent is volatilizable and can beselected from the group consisting of ethanol, methanol, acetone,dichloroethane, chloroform, and combinations thereof. In the presentembodiment, the organic solvent is ethanol. After being soaked by theorganic solvent, microscopically, carbon nanotube strings will be formedby adjacent carbon nanotubes in the carbon nanotube film, that are ableto do so, bundling together, due to the surface tension of the organicsolvent. In one aspect, part of the carbon nanotubes in the untreatedcarbon nanotube film that are not adhered on the substrate 22 willadhere on the substrate 22 after the organic solvent treatment due tothe surface tension of the organic solvent. Then the contacting area ofthe carbon nanotube film with the substrate 22 will increase, and thus,the carbon nanotube film can more firmly adhere to the surface of thesubstrate 22. In another aspect, due to the decrease of the specificsurface area via bundling, the mechanical strength and toughness of thecarbon nanotube film are increased. Macroscopically, the film will be anapproximately uniform carbon nanotube film.

Unlike previous methods for making an ITO film, the present method doesnot require a vacuum environment and heat processing, due to the carbonnanotube film being obtained by being pulled out from an array of carbonnanotubes. Thus, the carbon nanotube layers formed by the carbonnanotube films and used in the transparent conductive layer 24 have theadvantage of being low cost, environmentally safe, and energy efficient.

It is to be noted that the shape of the substrate 22 and the transparentconductive layer 24 is chosen according to the requirements of the touchfield of the touch panel 22. Generally, the shape of the touch field maybe triangular or rectangular. In the present embodiment, the shapes ofthe touch field, the substrate, and the transparent conductive layer 24are all rectangular.

Due to the transparent conductive layer 24 being rectangular, fourelectrodes 28 are needed and formed on the surface thereof, therebyobtaining an equipotential surface. Specifically, the substrate 22 is aglass substrate. The electrodes 28 are strip-shaped and formed ofsilver, copper, or any alloy of at least one of such metals. Quitesuitably, the electrodes 28 are disposed directly on a surface of thetransparent conductive layer 24 that faces away from the substrate 22.The electrodes 28 are formed by one or more of spraying, electricaldeposition, and electroless deposition methods. Moreover, the electrodes28 can also be adhered to the surface of the transparent conductivelayer 24, e.g., by a silver-based slurry.

Further, in order to prolong operational life span and restrict couplingcapacitance of the touch panel 20, the transparent protective layer 26is disposed on the electrodes 28 and the transparent conductive layer24. The material of the transparent protective layer 26 can be selectedfrom a group consisting of silicon nitride, silicon dioxide,benzocyclobutenes, polyester film, and polyethylene terephthalate. Thetransparent protective layer 26 can be a slick plastic film and receivea surface hardening treatment to protect the electrodes 28 and thetransparent conductive layer 24 from being scratched when in use.

In the present embodiment, the transparent protective layer 26 issilicon oxide. The hardness and thickness of the transparent protectivelayer 26 are selected according to practical needs. The transparentprotective layer 26 is adhered to the transparent conductive layer 24,e.g., via an adhesive.

The touch panel 20 can further include a shielding layer 25 disposed onthe second surface 222 of the substrate 22. The material of theshielding layer 25 can be indium tin oxide, antimony tin oxide, carbonnanotube film, and/or at least one other conductive material. In thepresent embodiment, the shielding layer 25 is a carbon nanotube film.The carbon nanotube film includes a plurality of carbon nanotubes, andthe orientation of the carbon nanotubes therein may be arbitrarilydetermined. Beneficially, however, the carbon nanotubes in the carbonnanotube film of the shielding layer 25 are arranged along a samedirection. The carbon nanotube film is connected to ground and acts asshielding, thus enabling the touch panel 20 to operate withoutinterference (e.g., electromagnetic interference).

Referring to FIG. 5, a display device 100 includes the touch panel 20, adisplay element 30, a touch panel controller 40, a central processingunit (CPU) 50, and a display element controller 60. The touch panel 20is connected to the touch panel controller 40 by an external circuit.Quite suitably, the touch panel 20 can be spaced at a distance 106 fromthe display element 30 or can be installed directly on the displayelement 30. The touch panel controller 40, the CPU 50 and the displayelement controller 60 are electrically connected. The CPU 50 isconnected to the display element controller 60 to control the displayelement 30.

The display element 30 can be, e.g., a liquid crystal display, fieldemission display, plasma display, electroluminescent display, vacuumfluorescent display, cathode ray tube, or another display device.

When the shielding layer 25 is disposed on the second surface 222 of thesubstrate 22, a passivation layer 104 is disposed on and in contact witha surface of the shielding layer 25 that faces away from the substrate22. The material of the passivation layer 104 can, for example, besilicon nitride or silicon dioxide. The passivation layer 104 can bespaced at a distance 106 from the display element 30 or can be directlyinstalled on the display element 30. When the passivation layer 104 isspaced at a distance from the display element 30 two or more spacers 108can be used. Thereby, a gap 106 is provided between the passivationlayer 104 and the display element 30. The passivation layer 24 canprotect the shielding layer 22 from chemical or mechanical damage.

In operation, voltages are applied to the electrodes 28 respectively. Auser operates the display device 100 by pressing or touching thetransparent protective layer 26 of the touch panel 20 with a touch tool,such as a finger, or an electrical pen/stylus 70, while visuallyobserving the display element 20 through the touch panel 20. In theillustration, the touch tool is the user's finger 70. Due to anelectrical field of the user, a coupling capacitance forms between theuser and the transparent conductive layer 24. For high frequencyelectrical current, the coupling capacitance is a conductor, and thusthe touch tool 70 takes away a little current from the touch point.Currents flowing through the four electrodes 28 cooperatively replacethe current lost at the touch point. The quantity of current supplied byeach electrode 28 is directly proportional to the distances from thetouch point to the electrodes 28. The touch panel controller 40 is usedto calculate the proportion of the four supplied currents, therebydetecting coordinates of the touch point on the touch panel 20. Then,the touch panel controller 40 sends the coordinates of the touch pointto the CPU 50. The CPU 50 receives and processes the coordinates into acommand. Finally, the CPU 50 sends out the command to the displayelement controller 60. The display element controller 60 controls thedisplay of the display element 30 accordingly.

The properties of the carbon nanotubes provide superior toughness, highmechanical strength, and uniform conductivity to the carbon nanotubefilms of the carbon nanotube layers. Thus, the touch panel and thedisplay device adopting the carbon nanotube films are durable and highlyconductive. Further, the pulling method for fabricating each carbonnanotube film is simple, and the adhesive carbon nanotube films can bedirectly disposed on the substrate and on each other. As such, themethod for fabricating the carbon nanotube films is suitable for themass production of touch panels and display devices using the same, andreduces the costs thereof. Furthermore, the carbon nanotube film stackhas high transparency, thereby promoting improved brightness of thetouch panel and the display device using the same. Finally, since thecarbon nanotubes have excellent electrical conductivity properties, eachcarbon nanotube layer formed by a plurality of carbon nanotubes orientedalong a same direction has a uniform resistance distribution. Thus thetouch panel and the display device adopting the carbon nanotube layershave improved sensitivity and accuracy.

Finally, it is to be understood that the above-described embodiments areintended to illustrate rather than limit the invention. Variations maybe made to the embodiments without departing from the spirit of theinvention as claimed. The above-described embodiments illustrate thescope of the invention but do not restrict the scope of the invention.

1. A touch panel comprising: a transparent substrate; a transparent conductive layer comprising at least two stacked carbon nanotube layers, each carbon nanotube layer comprising a plurality of carbon nanotubes substantially aligned along a single direction, and the carbon nanotubes in two adjacent carbon nanotube layers are substantially aligned along the same direction; and at least two electrodes being electrically connected with the transparent conductive layer.
 2. The touch panel as claimed in claim 1, wherein each carbon nanotube layer comprises one carbon nanotube film or a plurality of coplanar carbon nanotube films.
 3. The touch panel as claimed in claim 2, wherein the carbon nanotube film comprises a plurality of successively oriented carbon nanotube segments joined end to end by the van der Waals attractive force therebetween.
 4. The touch panel as claimed in claim 3, wherein each carbon nanotube segment comprising the plurality of carbon nanotubes that are combined by van der Waals attractive force therebetween.
 5. The touch panel as claimed in claim 2, wherein a thickness of the carbon nanotube film is in an approximate range from 0.5 nanometers to 100 micrometers.
 6. The touch panel as claimed in claim 1, wherein the carbon nanotubes in the carbon nanotube layer are selected from a group consisting of single-walled carbon nanotubes, double-walled carbon nanotubes, and multi-walled carbon nanotubes.
 7. The touch panel as claimed in claim 6, wherein diameters of the single-walled carbon nanotubes are in an approximate range from 0.5 nanometers to 50 nanometers, diameters of the double-walled carbon nanotubes are in an approximate range from 1 nanometer to 50 nanometers, and diameters of the multi-walled carbon nanotube are in an approximate range from 1.5 nanometers to 50 nanometers.
 8. The touch panel as claimed in claim 1, wherein the two electrodes are disposed on a surface of the transparent conductive layer.
 9. The touch panel as claimed in claim 8, wherein the electrodes are adhered to the surface of the transparent conductive layer by a silver-based slurry.
 10. The touch panel as claimed in claim 9, wherein the electrodes are metal electrodes.
 11. The touch panel as claimed in claim 1, further comprising a transparent protective layer disposed on a surface of the transparent conductive layer.
 12. The touch panel as claimed in claim 11, wherein the material of the transparent protective layer is selected from a group consisting of silicon nitride, silicon dioxide, benzocyclobutenes, polyester film, and polyethylene terephthalate.
 13. The touch panel as claimed in claim 1, wherein the material of the substrate is selected from a group consisting of glass, quartz, diamond, and plastic.
 14. The touch panel as claimed in claim 1, further comprising a shielding layer disposed on a surface of the substrate.
 15. The touch panel as claimed in claim 14, wherein the material of the shielding layer is selected from a group consisting of indium tin oxide, antimony tin oxide, and a carbon nanotube film.
 16. A display device comprising: a touch panel comprising: a transparent substrate; a transparent conductive layer comprising at least two stacked carbon nanotube layers, each carbon nanotube layer comprised of a plurality of carbon nanotubes arranged along a same direction, the carbon nanotubes in two adjacent carbon nanotube layers are substantially aligned along the same direction; and at least two electrodes being electrically connected with the transparent conductive layer; and a display element positioned opposite and adjacent to the touch panel.
 17. The display device as claimed in claim 16, further comprising a touch panel controller, a central processing unit, and a display element controller electrically connected to each other, the touch panel controller being connected to the touch panel, and the display element controller being connected to the display element.
 18. The display device as claimed in claim 16, wherein the touch panel is spaced from the display element with a distance.
 19. The display device as claimed in claim 16, wherein the touch panel is located on the display element.
 20. The display device as claimed in claim 16, further comprising a passivation layer disposed on the touch panel and the passivation layer being comprised of one of silicon nitrides and silicon dioxides. 